Adopt PEP 517 tooling for Python packages #

• Date proposed: 2022-02-19
• RFC MR: https://gitlab.archlinux.org/archlinux/rfcs/-/merge_requests/0010

Summary #

Replace setup.py with PEP 517 tooling (python-build/python-installer) for all Python packages where this approach is viable.

Motivation #

There are two main points.

Direct setup.py calls are deprecated #

The setuptools upstream has deprecated direct setup.py calls, and plans to remove support for them in the future. Please see setuptools#2088 and setuptools#2080 for more context.

setup.py install calls install old-style Python metadata #

The metadata installed by setup.py install is the old-style "egg" format (.egg-info). This is essentially implementation-defined by setuptools and has been replaced by a standardized format (.dist-info). By moving to the PEP 517 tooling, we will be using the wheel format, which has the standardized metadata.

Specification #

The change consists of replacing setup.py invocations with the python-build and python-installer tools.

Essentially replacing

python setup.py build
python setup.py install --root="$pkgdir" --optimize=1

with

python -m build --wheel --no-isolation
python -m installer --destdir="$pkgdir" dist/*.whl

You can find more information in the Python packaging guidelines.

This would naturally only serve as a general guideline, packages that need an alternative approach can still do so, but are recommended to stay as close as the guidelines as reasonably possible.

Drawbacks #

This change affects a big number of packages, so it will require some work per part of the maintainers, but it can be done incrementally as packages are updated.

Unresolved Questions #

None.

Alternatives Considered #

I don’t think there is currently any viable alternative solution for the issues presented.